Thursday, December 5, 2013

History & Development:
Really to grasp what the WZ.96 Beryl is, one needs to go back to the
days of communism and the Cold War. Soviet Russia developed and adopted
the 5.45x39mm M74 cartridge in direct response to the United States' use
of the .223 round in Vietnam. Many in the USSR at that time felt that
the Americans were technologically ahead when it came to smallarms. They
felt that if they had a small caliber, intermediate rifle round; that
Russia too must have a small caliber, intermediate round. Thus the AKM
was redesigned to fire a scaled down cartridge. 7.62x39mm turned into
5.45x39mm.
The new rifle and round started to be fielded in the USSR around 1977
and first saw extensive combat use in Afghanistan in 1979. Seeing an
oppertunity to force greater standardization within the Warsaw Pact,
Russia put pressure on its 'allies' to fall in step and also adopt the
AK74 platform. Bulgaria and East Germany did just that, first buying
rifles and ammunition from the USSR, and later producing close domestic
copies. Romania and Poland however, decided to be a bit more
independent. Both did adopt the 5.45x39mm round, afterall they did not
have much choice, but they insisted on creating their own rifles to go
along with it.
Romania's efforts resulted in the PA.86 assault rifle, and Poland's
yielded the WZ.88 Tantal. Both were based on the AKM as both nations had
all of the tooling and experience from two decades of producing their
own domestic copies using original Soviet blueprints.
The Tantal had a long, and at times rocky development process. Work
began in 1981 and the final version was not ready until 1988, by which
time the political climate in Poland was starting to change. The reason
for this protracted design period was that the communist government over
estimated the abilities of its firearms designers and under estimated
just how much work goes into a new design. Yes, the Tantal was based on
the AKM, but the Polish military requested several new features, such as
the ability to launch new types of rifle grenades and to have 3 round
burst capability. The design underwent several revisions throughout the
1980s. In the end, Radom did deliver a solid assault rifle. More
importantly though, its designers and workers learned a lot about
firearms manufacturing. They also created a short 'carbine' version
named the Onyks, though it was never built in large numbers.
The final Tantal prototype was ready by 1988 and was officially adopted
into military service the following year as the KBK WZ.88. However, by
that time, communism was on its way out in Poland after a June 1989,
election went against the party. Lasting change rarely happens overnight
and it took some time for Democracy to take root. Also, there were
still nearly 400,000 Soviet Russian troops stationed within Polish
boarders. So that nation adopted an outward stance of neutrality; trying
to distance itself from the Communist East but not yet ready (or able)
to openly ally itself with the Democratic West.
In 1990, it was estimated that Radom could produce 70,000 assault rifles
per month. AFter a decade of investing in the Tantal, the military did
begin to issue it in numbers in 1991, but really no one by that time
wanted it. Actually, what they didn't want was its 5.45x39mm caliber,
which was viewed as something forced upon them by their former masters
in Moscow. The Polish government purchased only about 25,000 Tantals
from 1989 through 1992, a tiny fraction of Radom's total capable output.
So what was the factory to do to keep itself in business?
A solution was hit upon by the factories leaders, who were just
beginning to realise the possibilities of the free market. Radom would
reinvent itself as a supplier of high quality but affordable smallarms
to the 3rd World (and whoever else was interested and paid with hard
cash). To this end, the WZ.88 Tantal was reworked to fire the 5.56x45mm
NATO cartridge and designated as the WZ.91. This was done as it was
believed the NATO round would appeal to more buyers. The 5.45x39mm never
obtained the same popularity as the older 7.62x39mm, especially in
non-communist nations. It was a step in the right direction for Radom
and soon there after, the WZ.89 Onyks was also reworked to fire the NATO
caliber; receiving the designation of WZ.92.
Meanwhile in politics, the Warsaw Pact slowly fell apart throughout the
Spring and Summer of 1991. In August of that year, Boris Yelsin was
coming to power in the USSR, which would fall apart itself and cease to
be by the New Year. After securing his position as Russia's new
Democratically elected leader, Yelsin began pulling former Soviet troops
out of other East European nations, including Poland. After half a
century of what was essentially occupation, the last Russian soldier
left Polish soil in September of 1993. Now the nation was truely free to
chart its own path and decide its own future.
A lot happened naturally, but I am trying to focus on what is most
relevant to the story of the Beryl. Basically, after the fall of the
Warsaw Pact and the collapse of Communism in Russia, NATO began to
invite former member states to join its organization. Poland was
interested and in 1994, it committed itself to a path where in it would
become a NATO member state by the end of the decade.
This meant that its military needed to meet several requirements, so it
could work with other NATO members, including standardization of
calibers and equipment. With great joy, the Polish declared the
5.45x39mm cartridge obsolete and designated 7.62x39mm as a substitute
standard to be used for training and reservists. 5.56x45mm SS109 was to
be the new general issue small rifle round, and a new rifle was needed
to fire it. Other requirements were that the new platform needed to be
able to fire standard 22mm NATO rifle grenades, have 3 round burst in
addition to full-auto, be no longer than 944mm when stored, and that it
had to more easily be able to mount scopes, sights, and other optical
devices. The military wanted both a standard rifle and a carbine version
in the new weapons family. In early 1995, Radom promised to have a
working prototype ready in just 9 months. It just had to decide what it
should be and how to build it.
The starting point was the short-lived WZ91. It showed promise, but it
was clear that it was a rush job and a conversion; not a ground-up
design. Still, Radom had decades of experience building AK rifles, not
to mention tooling and trained workers. It was decided then that the new
rifle would continue to be based on the AK platform. The new project
was given the codename of Beryl. Radom went over its allotted 9 months,
but not by much. By December of the same year, it had a few prototypes
ready for military evaluation.
In the following January, the military gave the factory a list of
changes it would like to see made to the new design. All were rather
minor and Radom found them easy enough to make. In May, it was announced
that the new rifle was acceptable and was scheduled for adoption. At
the end of the summer, an agreement was reached inwhich Radom promised
to deliver a second prototype batch of rifles and carbines. This batch
was delivered for testing in January of 1997, and two months later the
Beryl was officially adopted into Polish military service as the KBS
WZ.1996. The carbine became the KBK WZ.1996 Mini Beryl.
The new assault rifle quickly replaced nearly all of the older WZ.88
Tantals in military stores, though several AKM and AKMS rifles in
7.62x39mm were kept for a few years. The WZ.96 underwent nearly
continuous upgrades and revisions over the next decade. Many changes
were made based upon feedback given by actual soldiers who were issued
the rifle. Unlike the WZ.88 Tantal, the Beryl saw extensive use in real
combat. In March of 2002, as part of NATO, Poland sent troops to fight
in Afghanistan. Then in May of 2003, it also sent soldiers to assist in
Iraq. It was this tour of duety that would really shape and hone the
rifle into the one we see today.
Despite several successes in the 1990s, the old communist era leaders
still weren't quite able to make the Radom factory financially
profitable. As a result in 2002, it was declared bankrupt, but its doors
would not remain closed for long. The old communist ran Zaklady
Mechaniczne Lucznik Radom firm would be reorganized and reopened under
its original pre-World War II name of Fabryka Broni w Radomiu. The old
11 in a circle factory code used by ZM Radom, would also be replaced by
an FB in a triangle. After the reorganization, funding was put into
updating and modernizing the factory itself. New tooling and machinery
were purchased, and workers have been retrained with 21st century
techniques. Today, FB Radom continues to build rifles and pistols for
the Polish military, the civilian shooting market, and for export sales.
It seems to be doing quite well, but only time will tell how successful
it will become. The Beryl itself also seems to be a success. It was
estimated in 2011, that the Polish military had 45,000 of the firearm,
which was half of its total inventory. So already it has surpassed the
Tantal.

The Beryl Assault Rifle:
For sometime now, it has been a tradition with Radom to nickname their
firearms based on names from the Periotic Table. Thus the Beryl is named
for the element of beryllium. Based on the older WZ.88 and WZ.91
designs, the WZ.96 is an AK, using a standard long-stroke gas piston
system, with a 2 lug rotating bolt. The Fire Control Group is very
similar to the one found in the Tantal. There is a normal AK pattern
lever on the right side, but it only works as a safety. The lever
located on the left side of the receiver is used to set the weapon for
either semi-auto, 3 round burst, or full-auto. The Beryl has a 18" long
chromelined barrel, with a 1 in 9 twist rate. Radom selected this twist
so the firearm could handle both modern SS109 and older M193 ammunition
types. Somewhat unique among AKs, the muzzle brake isn't screwed onto
the barrel. Rather it is pressed and pinned on, in a similar manner to
how the front sight and gas blocks are attached. The device also can
launch standard NATO 22mm rifle grenades and accept a bayonet ring. The
weapon's receiver is made of 1.0mm stamped steel and is the same as that
of the WZ.88, except it has a 3rd rivit in the rear trunion to provide
for a bit more strength.
The Beryl takes the same pattern of furniture as the WZ.88 too,
including handguards and buttstock. That said, Radom designed a new
forearm made of ribbed black polymer for it. A new right side folding
tubular stock was also developed. It seems to have been inspired by the
one found on the Israeli Galil. It is made of steel, which is coated in
plastic shrinkwrap, and with a rubber buttplate. It fits into the
standard AKM rear trunion, same as the older 'fire poker' wirefolder of
the Tantal.
Probably the single biggest design feature of the rifle is its ability
to accept the Podstawa Optycznych Przyrzadow Celowniczych (Optical Sight
Mounting Interface, or POPC for short). This system mounts a rail over
the center line of the dustcover, so that sights and scopes can easily
be installed. It is secured to the firearm by two anchor points; one cut
into the rear sight base and the other ontop of the rear trunion. The
POPC system is easily removed for cleaning and is supposed to return to
zero when reinstalled.
The WZ.96 is commonly issued with 4 magazines in a nylon pouch, along
with a bipod, bayonet, rollup cleaning kit, sling, and 2 piece sectional
cleaning rod (which is kept in the mag pouch).
The Beryl first adopted in 1997, is not the same Beryl commonly seen in
the hands of Polish soldiers today. Radom has worked hard to modernize
and improve the design. For example in 1999, the Tantal style manual
dustcover latch, intended to keep the cover on when firing rifle
grenades, was replaced with a new pattern of automatic latch. This latch
locks itself if not pressed down. It does complicate dis/reassembly
however. In 2002, the left side fire mode selector was redesigned.
Originally, it was the same as the one found on the Tantal, and Radom
improved it by developing a new spring detent system and adding a second
arm. These changes make the selector easier to reach and use, and make
it less likely that it will be accidently bumped to a different setting.
Soon after this change, the magazine release catch was enlarged and the
right side safety lever received a finger shelf. Both changes were
aimed at making the Beryl more ergonomic. In 2004, using recommendations
from soldiers serving in Iraq, a new forearm was introduced for the
rifle. It is a modified piece with a removable vertical foregrip and
polymer side rail sections, for attaching lights or lasers. Finally, the
following year, the Galil style sidefolding stock was replaced with one
inspired by the collapsing stock of Colt's M4 carbine. Radom's
collapsing stock has a slim metal squared off tube, which supports a
heavy duety polymer stock with large rubber buttplate. The stock has a
total of 4 positions, a CAR15 style sling bar, and does not fold. Along
with the new stock, an ambidextrous sling loop appeared on the handguard
retainer.
The magazine of the WZ.96 has also been improved over time. Originally,
the rifle was issued with 30 round black polymer mags, which were very
similar to late production 5.45x39mm mags from Radom. These mags were
solid and reliable, but the 21st century trend is towards clear mags, so
the ammunition level can easily be discovered. Radom, wanting to keep
up with modernity, began shipping clear polymer mags with their rifles.
These mags prooved to be brittle and unreliable. The polymer mix just
wasn't that strong and the mags would easily develop spider web cracks.
Arsenal in Bulgaria has had a similar problem with its own clear 5.56mm
AK mags, it should be added. Anyway, so now the Beryl is being issued
with a third mag variation. This one is made of an updated polymer mix,
which is translucent green in appearance. It seems to be holding up much
better, but since it does not have metal reinforced locking tabs, it is
still not as durable as other AK mags.
Less we forget, the POPC system too has undergone several updates since
it was first introduced in the late 1990s. The original POPC was a long
rail mounted over the entire dustcover, however it used a proprietary
mounting system for optics. Sights had to be specifically made to fit it
and could not fit rails on other firearms. This was obviously a poor
decision by the designers, so the second generation rail was weaver
compatable. However, this rail was shorter and only mounted to the rear
sight base by the use of a set screw. It was not as stable and gave only
limited sighting options. The POPC generation 3 rail returned to the
original long pattern which anchored in both the front and back, and
this time it was weaver compatable. This meant it could mount a wide
range of devices and was solidly attached to the firearm. Its only major
drawbacks were that it blocked the iron sights and a small group of
optics still wouldn't fit it properly. The current generation 4 rail
system addresses really all earlier shortcomings. It is fully Picatinny
compatable, so all standard devices will easily fit it. It even allows
for the use of the Beryl's traditional iron sights as they are visible
through a trawf running under the rail. It is lighter and more durable
than earlier models too. This version of the POPC has been out for a
number of years now, and seems to be the one that Radom and the Polish
military are happy with.
As you can see, the WZ.96 Beryl has changed quite a bit over a
relatively short period of time. In fact, it is different enough now,
that newer models are receiving the designation of WZ.2004. Generally
speaking the WZ.2004 has the newer style of handguard with vertical grip
and has one of the more recent POPCs on it, usually a Gen 3 or Gen 4.
Most have the collapsing buttstock, and a few have received a new
pattern of pistol grip, designed to be more ergonomic.
The Mini Beryl is also seeing limited use by both Polish military units
and police officers. It is very similar to its parent design and took
inspiration from the compact WZ.89 Onyks. The Mini Beryl's barrel is
nearly half as long as that of the Beryl, at 9.3". It has a shortened
gas system, redesigned handguards, and alternative flash hider. It is
sometimes used with a 20 round magazine. The Mini has received most of
the same updates as the standard Beryl.

The Archer Sporting Carbine:
The Archer-01 is the first civilian legal, semi-automatic version of the
WZ.96 to be imported into the USA, at least in any real numbers. It is
built by FB Radom in Poland, and carries over many of its full-auto
cousin's features. It is chambered for 5.56mm NATO and has a 18"
chromelined barrel, with a 1 in 9 twist rate. It takes standard WZ.96
furniture, including handguards, pistol grips, and buttstocks. Probably
most importantly, it comes from the factory ready to mount the POPC rail
system. It also has the enlarged mag catch release, extended shelf
safety, ambidextrous forward sling loops, and standard iron sights.
Of course the Archer is different from the Beryl in a number of ways
too, to make it acceptable to the American government. The receiver is
made in Radom as a single-stack only, meaning it feeds from low-cap 10
round magazines. Naturally, this receiver lacks the 3rd axis pin hole,
so it is not legally select-fire. The left side fire mode selector is
omited for this reason too. Since Radom never expects anyone to use the
Archer to launch grenades, it has only 2 rivits in the rear trunion,
rather than 3; however the trunion itself could accept the 3rd rivit if
desired. It also does not have the automatic dustcover latch found on
the military WZ.96; which is actually probably a good thing based on how
unpopular that feature seems to be with Polish troops. Finally, the
Archer's bolt carrier is milled so it can not trip an auto-sear. This is
done on other imported AKs such as the Romanian Cugir WASR10, Arsenal
SLR, and Russian FIME SGL series. Also like other imported AKs, the
Archer ships from Poland with a sporting legal thumbhole buttstock.
The rifle is imported into the USA by Royal Tiger down in Florida. Once
on American soil, the Archer is modified to make it more marketable. The
single stack magwell is opened up to allow it to feed from standard 20
and 30 round Beryl magazines. Next, the thumbhole stock is replaced with
a military stock and pistol grip. Then to give the rifle enough 922(r)
parts, the Polish semi-auto trigger group is replaced with a US made G2
group from Tapco. One contraversial feature of the Archer is its manual
bolt hold back safety lever. The lever has a cutout which can hold the
charging handle back, but it has to be done manually. Most people say
that RT cuts on the safety in the USA, but I've read from a few sources
that actually Radom does the work in Poland, on request from RT. The
notch does seem to work fine, at least on the 4 or 5 Archers I myself
have handled. RT claims this is the first AK rifle to have a BHO, but
Century has been importing several firearms with the same notched safety
from Zastava in Serbia. These include the PAP M70, NPAP M70, M85PV, and
M92PV.
Archers have come in a few different configurations over the past year.
The original ones had a screwed on muzzle brake, not unlike that found
on the Tantal. They also sported fixed clubfoot polymer stocks, and did
not come with any scope rail system. People complained, especially about
the incorrect barrel profile, so the second batch of rifles, known as
v2s by collectors, addressed their concerns. V2 rifles have a proper
Beryl profile barrel, which is to say unthreaded. They came with a small
muzzle brake, which is supposed to be pressed and pinned onto the
muzzle. This brake is Polish, but sent to Royal Tiger by Radom separate
from the rifles. RT installs it, but doesn't seem to pin it. I am not
sure how they attach it in place. Both hilarious and sad, some of the
earlier v2s had their muzzle brakes installed by RT upside down! In all
other ways, v2s are the same rifles as the original v1s. They do not
include the POPC system and come with the same clubfoot fixed buttstock.
However, starting this year, RT began shipping them with an original
Radom WZ.2004 collapsing buttstock loose in the box, which the buyer
could install if desired. Originally, rifles shipped with 2 30 round
Green Beryl mags, military sling, and cleaning kit. After a couple
months though, RT started sending only 1 Beryl mag instead. Just
recently, RT changed things up again. Now, Archers are beginning to ship
with the collapsing buttstock already installed from the factory, and
the muzzle brake put on correctly. Most importantly though, the latest
Archers are coming with the current generation POPC rail system on them.
There is a price for these upgrades of course. Rifles ship with 1
American made black waffle mag from Pro-Mag and nothing else.
As to pricing, the rifles have slowly but steadily come down a bit. When
they first came out, they were $1,400+ and did not have the correct
stock or rail. Over several months, prices dipped down to as low as
$1,200, and once RT had a $1,000 blowout sale on them. Now that they are
coming with the right stock and rail, Archers are back up to around
$1,300 but at least they are pretty much good to go out of the box.
Though I'd recommend finding some decent magazines to use in them true.
(Archer w/o Rail)

(And with current generation rail system.)

(And with an Eotech 552 installed.)

(My Tantal kit built on a Nodak receiver, just for fun.)

Converting an Archer Into a Beryl Clone:
Actually, with the latest Archer-01 version, there isn't a ton to do. It
already comes with a Polish buttstock, handguards, and rail. It has the
proper barrel profile, with Polish made brake. This brake has the same
port arrangement as the one on the WZ.96 and even the cutout for the
grenade ring. The only thing it is missing is the internal threading to
accept a blank fire adapter. Also, if one wanted to be a purest, they
could also drill it and the barrel, and pin it in place like Radom does
on their military contract rifles. Both the front sight block and gas
block have the spots for the bayonet and accessory lugs, just they
haven't been milled out. It wouldn't be much work for a skilled
machinist to finish out the lugs and add a bit of touchup to the
parkerization. This is a far better idea than milling off the bayonet
lug wings, like Cugir does to the WASR10. The gas block does have the
cutout to allow the Beryl bipod to fit onto it. The only thing missing
here is the small rod which prevents the bipod from being rotated 360
degrees. This rod could be fabricated if needed as its the same size as a
Tantal cleaning rod.
Moving down the rifle, it has true Radom made handguards. These are the
horizontal type used on earlier WZ.96 models, and they even still have
the little cutouts for the grenade launcher on the bottum. Its easy to
swap out Beryl/Archer handguards, so if someone wants the current type
with vertical grip and rails, no problem. RTG has two types at the
moment; one made of polymer and one of metal alloy. The Archer's sights
and dustcover are the same as on the military rifle, as are the mag
catch, safety selector, and front trunion. The BHO notch in the safety
bugs some and they like to remove the piece and replace it with one that
isn't cut out. This is easy to do and doesn't even require 3 hands or
tools. On the left side of the receiver, there is no fire mode
selector. Radom (and the Polish gov't for that matter) consider this
part as the key to making a full-auto, so it is not installed on
civilian rifles. However, it can easily be put onto an Archer. All that
needs to be done is to remove the bar that the safety rides on, and
replace it with the selector assembly. Since the Archer has no 3rd axis
pin or auto-sear, the left selector doesn't do a thing, except look
military. A person can link it to the safety lever on the right side, to
make it into an ambidextrous safety if they want to. This is what
Century did in their Tantal Sporters, and it is completely legal and
safe. The only downside is the left selector switch tends to be rather
stiff.
At the rear of the rifle, we only have a couple things we could do, to
make it look more like the Beryl. It already has the current issue
collapsing buttstock, but the older Galil style sidefolder will drop
right in instead, if the owner prefers that look. The collapsing stock
even comes complete with the internal reinforcing plate/bracket, so no
corner cut there. The pistol grip is clearly US made and not much like
the one Radom uses. Polish military grips are everywhere and easy to
install. The Tantal used various coloured grips from brown to orange to
black, but the Beryl seems to always have a black grip. As i said
earlier, the Archer doesn't have the automatic lockout latch found on
the military WZ.96. This latch is to keep the dustcover from flying off
when a rifle grenade is fired. It is only successful at doing this
'most' of the time. It is however successful in complicating
dis/reassembly all of the time. Our semi-auto has the standard, normal
AKM takedown push button. It could be replaced with the auto latch if
one were found. The last thing we can do is to install a 3rd rivit in
the rear trunion. The trunion itself has the hole for it but the
receiver does not. This would require some skill and the nerve to rivit
on a factory receiver. Still it is doable if one really must have a
correct clone rifle.

My Opinion:
Initially, i was reluctant to get an Archer. Some of you know how i feel
about .223 AKs in general, and that is still the case most of the time.
On the otherhand, I've always liked the fact it is a true Polish built
AK; not too many of those available to us in the USA. Then again, when
the Archer came out, it was much more expensive than an Arsenal in .223
and it didn't come with enough original features to really excite me.
Well now it is a bit cheaper and more importantly, it is coming from
Royal Tiger setup very close to a real Beryl. These facts, combined with
continually good reviews from those who own them, finally convinced me
to order one and give it a chance. Plus honestly I was a bit bored and
wanting something new to mess around with.
So the Archer-01 came in and i was favourably disposed towards its fit
and finish, and overall feel. Then we took it shooting and....

...and it was a blast. Everyone loved shooting it and more rounds went
through it that day than did through the AUG and Tavor combined. The
Archer was easy to handle, comfortable, had good sighting, and above all
was dead reliable. It ate the Tula 62g stuff that choked both of the
bullpups we had out. I myself can't attest to Radom's claims of 1-MOA
accuracy, but Fell did say it was pretty much dead-on and he was easily
hitting what he was aiming at. It definitely seems to have accuracy a
cut above your normal AK at least.
I am making an exception to my no .223 AK rule, and designating the
Archer as a keeper. Yes, it isn't cheap, but really it isn't any more
than a good AR15 and to me far more unique and interesting.

What Sets It Apart From Other AKs:
> Built by a well respected factory, from new production parts.
> Designed from the beginning to fire both M193 and SS109 ammunition types.
> Designed to be as accurate as an AK can be with a top quality 18"
barrel, and close attention to tolerances and fitting of parts.
> Still as reliable and durable as any other AK.
> Has gone through extensive military testing, Radom product improvements, and has seen actual combat.
> For an AK, ergonomics are good with oversized controls and an adjustable LOP buttstock.
> Has arguably the best rail mounting solution developed for the AK platform yet.
> Uses good reliable magazines, which are pretty easy to find here in the USA.
> Cool and interesting factory markings, combined with a descrete importer's stamp.
> Its just damn enjoyable to shoot!

Summary - The Archer combines the reliability of the AK, with accuracy
on par with many production ARs. Its only real detraction is its
pricetag.

Introduction:
Back at the 2009 Shot Show, Century Arms introduced their Sterling
Sporter 9mm carbine. Some overseas military had surplused thousands of
British manufactured Sterling MK IV SMGs and Century purchased them;
cutting them up into parts kits. They then sent the kits to Wiselite to
be reassembled into legal semi-auto only carbines for the US civilian
market. I saw one of these Sterling Sporters in early 2009 and broke one
of my long standing rules: no open bolt to closed bolt conversion guns
in my safe. I just liked the feel and looks of the Sterling too much not
to have one. Actually, i purchased one for myself as a wedding gift in
August of that year.
It was a great carbine and I did a little thread on it. In that thread i
took some cheap shots at the older British Sten gun, to highlight many
of the Sterling's improvements. Forums member Sten Freak quickly put me
in my place by pointing out many of the Sten's admirable trates. So a
short time later i decided maybe having a semi-auto Sten would also be
neat.
I soon discovered there was a problem with this idea however, as no US
company had really ever mass produced a closed bolt semi Sten. So
finding a good reliable one wasn't easy. Eventually in 2011, i found an
old Catco SA2, which is a legal semi Sten MK II clone. Catco had a
mixed reputation and has long since been out of business. Still it was
really the only company that even came close to semi Sten mass
production; they themselves made a few hundred carbines and pistols back
in the late 1990s and early 2000s.
I bought the SA2 and was quite content with it. I thought that would be
it, and it was for about two years. It ran well and really looked the
part of a british WWII SMG. It went well with my Sterling Sporter too.
Then earlier this year, i found a good deal on a pair of preban British
made Sterlings and couldn't pass them up. I did a thread on them
already, which i will link to below for anyone who missed it and would
like to read it. After upgrading my Sterling, i thought it might be
worth looking into doing the same with my Sten. Now, there is no such
thing as a preban semi-auto British made Sten, so i was thinking it
might be nice to buy a parts kit and have another model built up. Also,
while the Catco was nice, it was not as authentic as i could have
wished. There were some things that could be done to make a legal semi
Sten closer to an original.
Long story short, through a friend I met a great gentleman down in
Florida who agreed to build me both a Sten MK II and MK V to my
specifications, from parts kits. He supplied the MK II kit and I had the
MK V. Even better, my friend sold me his MK III, which was also built
by the guy in FL. So now I have a nice set of 3 semi Stens, all done by
the same guy with the same high quality conversions. In each case, he
tried to keep them as original as possible, while sticking to the ATF's
rules.
While doing these builds with him, i collected a goodly bit of
information about the Sten machine carbine from WWII. Since I had
already done a thread on the Sterling, one for the Sten only seemed
natural.
Sten Freak has once again helped me a lot with information and
photographs. In addition, just recently, Apex has started offering all 3
major Sten variants as parts kits. So there is renewed interest out
there in semi-Stens, with kits on the market again.
So with all of that said, lets dig into the firearm which became nicknamed as the "Plummer's Abortion!"

Background & Development:
The now legendary Sten machine carbine was one of those developments
that was a long time in coming. The British expressed little interest in
the then new Submachinegun class of smallarm, which was first seen
during the last year of World War I. Development of the SMG continued
during the Interwar era, with the famous Thompson entering into
production in the early 1920s. Germany, Russia, and Finland all
developed their own during the 1930s also. Britan however, still lagged
behind and was not fielding an SMG when war broke out in 1939.
At the Battle of Dunkirk, the British Army lost a large number of
firearms and ammunition. While a good part of the men themselves were
successfully evacuated, much of their equipment had to be left behind.
As a result, the British had a sovear shortage of firearms to arm
themselves with, when the Battle of Britan began.
With the very real possibility of invasion of the British Home Islands
by Nazi Germany, the nation's leadership called for a new automatic
weapon, which could be produced quickly and cheaply, could be made from
existing materials, and something that soldiers could easily be trained
to use effectively in combat. In the summer of 1940, the call was put
out that the British Army was in need of a Submachinegun.
The first design to appear was the Lanchester, which was essentually a
British copy of the German MP28. The Lanchester even fed from MP28
magazines and used very similar parts. In August of 1940, 50,000 such
weapons were ordered from the Sterling Arms Co. They were meant for the
RAF, as airfield guard carbines, but by the time production was in full
swing, the RAF had found another SMG to fill the role. So instead, most
Lanchesters were given to the Royal Navy or to British Allies. At the
same time, the British were buying up as many Thompson M1928s as
Auto-Ordnance could supply. However, the SMG was in an uncommon caliber
for Europe and not nearly enough could be made available. The Thompson
was quite costly and time consuming to produce.
The Lanchester was a solid reliable gun, but was somewhat complex to
manufacture; costing nearly two dozen man hours to make and assemble
the parts. It was good, but Britan was looking for something better
suited to its hour of need.
Even as production for the Lanchester was getting underway in late 1940,
ROF Enfield was ordered to design an easily mass produced SMG, which
fired a common caliber. This of course would become the Sten, with the
first prototype tested a mear few weeks later in January of 1941.
The name 'Sten" is frequently explained as an acronem for the weapon's
designers. S for Major Reginald V. Shepherd, T for Harold J. Turpin, and
EN for ROF Enfield. Though a few sources claim the EN stands for
England; maybe both could even be true? The Sten's design was loosely
based on the MP28 and Lanchester, and also shared some features with the
MP38. It was made from many stamped metal parts, as well as
off-the-shelf piping and screws. In fact, really only two components,
the barrel and bolt, actually needed to be machined. Everything else was
easily fabricated in a basic machineshop. The Sten utilized spot welded
construction and did not require highly skilled labor to complete.
It was officially adopted into British service as the Sten Machine
Carbine MK I in the Spring of 1941. Production was quickly ramped up and
by the Summer, thousands were already being turned out, with components
made in dozens of factories all over England. The new weapon saw its
first major action in 1942 during the Dieppe Raid. The Raid itself did
not go terribly well for the Allies, however it did proove the Sten to
be a viable, if not perfect, combat weapon.

General Sten Info:
The Sten was a classic third generation SMG. It was built from many
stamped parts and fired from an open bolt. It could be set to either
single shot or fully automatic, by use of a very simple cross-button
selector. It had a 7.8" long barrel, with a heavy walled chamber. The
bolt was its other solid massive part, being a single heavy piece design
with fixed firing pin. It was intended to be milled from steel, however
in 1942 and 1943 Britan, steel was in short supply. So some Stens were
fitted with bolts made from cast bronze (often mistaken for brass).
Surprisingly, these bolts held-up ok in combat, though naturally they
had a shorter service life. Somewhat unique, the SMG's magazine well was
mounted to the left side of the receiver tube, with the magazine itself
sticking out horizontally. Sten magazines were of a double column,
single feed type, a design borrowed from the MP28. Their standard
capacity was 32 rounds, though older 50 rounders from the Lanchester
would also work in the Sten. Later on, some magazines would be modified
to hold 20 cartridges in a single column. This was done by some nations
such as Israel and India, to improve feeding.
The Sten never had much in the way of safety features. In the beginning,
its only real manual safety was a 'J hook' notch cut into the receiver
along the cocking handle's track. The bolt could be pulled back and the
cocking handle slipped into this notch, physically preventing the bolt
from moving forward. This system was at best only partially effective.
One major issue was if the bolt were forward and the SMG were bumped
hard enough, the bolt could move back far enough to strip a round from
the magazine, but not back far enough to engage the sear. The result
would be a run-away slam firing, thanks to the fixed firing pin on the
bolt face. After a few years, a new style of cocking handle was
introduced. When the bolt was forward, this new handle could be pressed
inward. Doing this would push the far end of the handle into a notch in
the receiver, thus locking the bolt in the forward position. Many older
Stens would be retrofitted with the improved safety system. Still yet,
the firearm never had a true manual safety, such as on the Thompson or
Suomi.
The Sten was designed from the beginning for mass production, and to
require as few resources as possible. The only two parts that actually
had to be milled, and thus required skilled labor, were the barrel and
bolt. Really all of the other parts could be made from stampings and put
together by workers with only minimal training. The SMG's receiver tube
and stock strut were made from tubing with the same diameters as
off-the-shelf piping. The screws even used a common thread pitch.
Relatively few welds were required to build a Sten, and they did not
need to be precise.
At the start of manufacturing, 1 Sten required roughly 12 man hours to
complete, which was half the time required to build a Lanchester SMG.
However, as time went on, workers gained experience, the design was
simplified, and production techniques improved, a Sten could be created
in as few as 5 man hours. The SMG had few parts, with the MK III version
actually having a total of only 47.
The Sten was produced by several factories, including: Royal Small Arms
Factory, Enfield, Singer Soing Machine, BSA, ROF Fazakerley, ROF Maltby,
ROF Theale, Berkshire, Lines Brothers Ltd, and Long Branch Canada.
Additionally, at least a dozen smaller firms were subcontracted with to
make individual components, which were shipped to the various main
facilities for use in final assembly. The vast majority of Stens were
built during World War II, between 1941 and 1945. No one knows exactly
how many were made, but estimates range from 3.6 to 4.7 million in
total, counting all variants.

The MK I & MK I*:
The first Sten variant was manufactured in 1941 as the MK I. It was to
be sure an economy weapon, but it did have a few refinements, which
would be removed on later models. For example it had its barrel fully
enclosed by a shroud and a basic muzzle brake at the end. It had a rifle
shaped metal skeletonized stock, similar to the later 'loop' stock but
more ornate. This stock had an attachment point for an Enfield rifle
type sling. It also had a foregrip made of wood or metal. About 100,000
of the MK I variant were built, before being replaced by the MK I*.
The MK I* featured the first of many cost savings changes to the Sten
design. It lacked the foregrip and brake, and no wood at all was used
during its construction. Also, the rifle sling mount was removed from
the stock. About 200,000 MK I*s were built during the latter half of
1941, most by Singer Soing Machine in England. These models were
intended primarily for use by ground forces, as they had barrels rivited
into the receiver tube, and fixed side feeding magazine wells. Only the
stock was easily removable. The metal parts received an inexpensive,
but decent enough chemical bluing treatment.

The MK II:
Shortly after the adoption of the MK I Sten, testing began on a second
model, intended for use by airborn and mechanized forces. It was
officially adopted as the MK II at the end of the Summer of 1941. The MK
II had further simplifications from the MK I* model, which made it both
faster and cheaper to mass produce. It used even more stamped parts,
required less fitting, replaced some rivits with welds, and had very
basic furniture. To make it easier for transportation and storage, it
featured a new style of magazine well, which could rotate down 90
degrees when not in use. It also had a barrel which could quickly and
easily be removed from the receiver in the field. As with all Stens, the
stock was very easy to detach also. These features made the MK II
perfect for paratroopers and easier to store in military vehicles.
The MK II had a shortened barrel shroud, which left several inches of
the barrel exposed. There was just barely enough room for a hand in
fact, it was so short. It had very basic fixed iron sights, with a blade
front and aperture rear. The cocking handle was little more than a
metal rod and there was no pistol grip at all in either the front or
back. Two types of stock were primarily used with the MK II. The 'loop'
stock as its known today was a simplified version of the original
skeletonized stock. The 't' stock was even more crude, with a single
piece of pipe surving as a strut, welded to a buttplate. The loop stock
was more comfortable and attractive, but the t stock prooved to be much
more durable, so it became the accepted standard in the British
military.
The first contract to build MK IIs was given to Long Branch in Canada in
late 1941. By the beginning of the following year though, several
factories in Britan were also turning out the new variant, including:
Enfield, Fazakerley, Theale, and BSA. No one knows for sure exactly how
many were produced during the war, but estimates range from 2,000,000 to
2,600,000, including all factories. Regardless of the actual number,
the fact is that the MK II was by far the most mass produced version of
the Sten gun. It saw widespread combat in the European Theatre
throughout the war. Many were also given to British Allies and
underground resistance movements fighting the Nazi Germans.

The MK III:
The MK III variant returned to the first generation layout of the Sten.
It was more like the MK I* than the MK II in otherwords. Its receiver
tube, barrel shroud, and magazine well were assembled together as a
single unit, and couldn't be separated without a torch. The barrel too
was rivited into the receiver and was covered mostly by the shroud. The
MK III was the simplest and cheapest Sten version ever fielded. It used
parts made mostly from stampings, including a receiver which was made as
a flat and then rolled up and welded into a tube. Some SMGs even had a
stamped sear, rather than one made from a milled piece of steel, as was
common on earlier Stens. Most parts were spot welded together, with few
rivits used. Rather than being held on with screws, the dustcover was
dimple pressed into place. The most common stock found on the MK III was
the 't' version. The MK III did have a few advantages over the MK II,
so it wasn't just an economy model. Its fixed magazine well did give it
improved reliability, and its longer barrel shroud was easier to use as a
handguard. It had an actual sling swivel on the underside (later some
SMGs would also have a second swivel added to their buttstocks), and a
small metal flap added in front of the ejection port. This flap was
meant to insure the shooter's hand did not move too far back on the
tube. Finally, some found the ridge ontop of the receiver, which was a
side product of the manufacturing process, made the weapon easier to
sight along and aim down.
Production of the MK III began around April of 1942, with Lines
Brothers, a toy manufacturer experienced in working with stamped metal
parts, being the biggest producer. IN all, approximately 900,000 SMGs of
this type were made during a 2 year run. As evidenced by its
configuration, this Sten was mostly meant for use by ground forces, like
the MK I before it. It was popular among military base and factory
guards on patrol.

The MK V:
After the tide of the war started to turn in favour of the British and
their allies, the need to economize in firearms production lessened. As a
result, after the very simplestic MK II, the next Sten would move back
towards a slightly more ornate design. The MK V featured a return to
wooden furniture, including both a buttstock and finger grooved pistol
grip. The stock mounted like any other Sten stock, but the introduction
of a true pistol grip meant that the lower trigger housing and dustcover
had to be slightly redesigned, with the trigger itself moved forward.
The buttplate was made of brass and even had a trapdoor to store a small
cleaning kit. The new model had an Enfield No. 4 type front
sightlocated on the end of the barrel. This sight was drift adjustable
for windage and had protective ears. A No. 4 bayonet could also be
mounted onto the MK V's muzzle. The cocking piece was enlarged, making
it easier and more comfortable to use. Early models also came with a
small wooden foregrip, however it was found to easily break and was thus
removed from the design.
Generally speaking, this model of Sten had better fit and finish than
previous ones. It also introduced a new method of treating the external
metal parts, which Britan would carry over to the Enfield and continue
to use on the L1A1 SLR. Where as earlier Stens were finished with a
chemical bluing process, the MK V featured a phosphate coating topped by
a black paint substance, which was more rust resistant. For all of its
unique appearance though, the final wartime Sten was simply a dressed up
MK II. It had the same removable barrel, short shroud, rotating
magazine well, and fixed aperture rear sight. It was no more reliable,
accurate, or safe to use than any other Sten. It did look more like an
American Thompson, which the higherups thought would inspire more
confidence with the troops. This really didn't proove to be the case in
the end. Soldiers didn't much care for the additional weight that the MK
V carried, thanks to its wooden furniture and more complicated barrel
assembly. So surprise, they cared more about a weapon's usefulness in
the field, than its superficial appearance.
About 525,000 MK Vs were built, with production beginning in February
1944, and lasting until shortly after the end of the war. The two main
factories responsible were Theale and Fazakerley. MK V production did
replace that of the MK III, however MK IIs continued to be made in
Canada and elsewhere. The MK V did see combat, mostly in Europe
following D-Day. It was most famously used in Operation Market Garden at
Arnhem, by British paratroopers.

Other Stens:
As you noticed, there is no MK IV listed above. This is because this
model never went into production. It was a compact version, basically a
'machine-pistol' with a 4" barrel, which was intended for paratroopers.
The version of the Sten manufactured by Long Branch Canada was similar
to the British MK II, but different enough that it was officially
designated as CMK II. The differences between the two versions were
minor, relating mostly to slightly different manufacturing techniques.
Also, the CMK II was normally built with the skeletonized loop stock.

There was also a MK II(s), which was a dedicated suppressed version of
the standard MK II. It had a perminant suppressor device, which was
quite effective at reducing audible noise. The trade off was that the MK
II(s) had a shorter effective range and was meant to be fired as a
semi-automatic only. Full-auto was reserved for 'emergency use only' as
using it would quickly wearout the suppressor. There is no hard evidence
to support the claim that bronze bolts were most often used in
suppressed Stens, as they were quieter than ones made of steel.

A silenced version of the MK III was designated as the MK III(s), and
the MK VI, breaking with tradition, was the name given to the silenced
version of the MK V.
Interestingly, in 1944 in Germany, DWM/Mauser built around 28,000
near-exact clones of the Sten MK II. These clones were correct right
down to the fake British proof markings and were nicknamed Gerat Potsdam
guns. No one knows for sure the purpose of these weapons but use your
imagination.

During the final year of the war, when Germany's factories were starved
for resources, Mauser once again turned to the Sten design, this time to
equip Germans to fight against the Allies. The MP.3008 Volks
Machinenpistole was a near exact copy of the Sten, with the biggest
difference being its vertically oriented magazine. It was produced with
copies of both the loop and t stocks, and a few examples have even been
discovered with basic stocks made of wood. What made the SMG attractive
to Britan in 1941, made it so for Germany in 1945. In all, about 10,000
were built, some made just days before the end of the war.
Thanks to its simple construction, many underground resistance movements
in Europe during WWII were also able to copy the Sten, and build their
own guns nearly from scratch. Again, the only two parts that really
needed to be built to withstand the stresses of firing were the barrel
and bolt. The other parts could be built from a wide range (and quality)
of materials. Both Norway and Poland were known to have built such
guns.
Also during the 1940s, Stens were cobbled together from whatever could
be found by Jews in what was then Palestine. These brave souls with home
made SMGs were the backbone of the movement, which would eventually
result in the formation of the modern state of Israel in 1948.
The Sten had a great influence on other SMGs designed during WWII too.
For example its barrel and bolt system were borrowed by Carl Gustav when
it was developing what would become the M/45, aka the Swedish K. Its
simple stamped steel construction would inspire Soviet engineers when
developing the PPS43, during the fight for Leningrad. The Sten would
have an equally strong influence when the Americans wished to replace
their expensive and complex M1 Thompson, with something better suited to
wartime mass production. Thus the M3 Grease Gun has many aspects
remenicent of the Sten, such as its receiver tube construction, sights,
and magazine.

After The War:
After the war, all 3 main versions of the Sten served together, side by
side in Common Wealth units around the world. The Sten was the standard
issue SMG in Britan, Canada, South Africa, and India. It was also in
widespread use in several other nations, including Australia and New
Zealand. So many were made during the war, and the design was so easy to
repair and keep running, that there were more than enough Stens to go
around without the need to build replacements.
This is why in part the British military was so slow in replacing the
Sten with the Sterling SMG. The Patchett MK I, the original model of the
Sterling, first appeared in 1944 and was even ready for field use by
1945. It was tested extensively and prooved itself superior to the Sten
and other SMGs but was not officially adopted into service until 1951.
Even then, it wasn't until 1956, that it went into widespread use. At
the same time, after adopting a new designation system for military
equipment, the British military renamed its various Sten models. The MK
II became the L50, the MK III the L51, and the MK V the L52. The Sten
was slowly phased out in favour of the Sterling during the late 1950s
and early 1960s, but it was a gradual process. It seems clear that the
military wasn't overly concerned with replacing the SMG which saw Britan
through one of its darkest hours. It hung on in Canada too, not being
replaced by the C1 Sterling variant until the mid to late 1960s. The
young Israeli Defense Force used it during the 1950s, before retiring it
in favour of their own Uzi SMG. The Sten went to Vietnam in the 1960s
in the hands of Australian, New Zealand, and even American soldiers. It
continued to see heavy use in Africa during the Cold War era, and
unlicensed copies were built in India, where it remained the standard
SMG until at least the 1970s. Finally, the Sten design had a strong
influence on various postwar SMG models created all around the world,
such as the American Ingram MAC-10 and S&W M76, German Walther MPL,
Argentine FMK-3, Belgian Vigneron M2, Bulgarian Arsenal Shipka (named
after a brand of cigarette by the way), Czech Vz.23 series, and numerous
others.

A Very Brief Look At The Sterling:
The Sterling SMG was the brainchild of George W. Patchett, who was the
chief designer at the Sterling Armaments Co. during WWII. As early as
1943, the British General Staff began to look into an improved model of
SMG and the following year, the Patchett MK I was ready for field
trials. However, the end of the war put an end to massive defense
spending in Britan, so for the rest of the decade the Patchett was
tinkered with and put into various trials.
That said, by the early 1950s, the British realised their standard issue
smallarms were horribly out of date. Actually, the Sten gun was one of
the more modern firearms their soldiers took with them to fight in
Korea. Otherwise, they carried the Lee-Enfield No. 4 (a bolt action not
dissimilar to the blackpowder Lee-Metford from the 1880s), the Enfield
No. 2 MK I* (a breaktop revolver based on the Webley, also first fielded
in the 1880s), and the Bren MK I and II (a pre-war LMG, which while
reliable and well made, had its own shortcomings with its roots in WWI).
So a crash program was begun to update British equipment.
The Sterling was one of the first new firearms to be adopted in 1951 as
the L2A1, and thanks to several years of refinement, it was basically
good to go right away. The L1A1 SLR, an FN FAL variant, replaced the old
Lee-Enfield in 1957; and while the Bren continued in service, it
received a facelift to become the L4A1.
Looking at the Sterling is really informative if one wants to discover
what the British felt were the critical shortcomings of the Sten. Like
the Sten, the Sterling used the 9mm Parabellum cartridge and fed from a
horizontally oriented magazine. It had a 7.8" barrel and fired from an
open bolt. There were major differences though.
The Sterling had a folding metal buttstock, along with a pistol grip
made of bakelite. Its magazine well was fixed and its sights were
adjustable for both windage and elevation. Both sights also had
protective ears. The Sterling's most important improvement was its
magazine. It was curved and held 34 rounds. It was of the double column,
double feed pattern. Somewhat unique, its follower had 2 rollers, which
gave it excellent reliability while also making loading faster and
easier. Interestingly, the Sterling's magazine well was reverse
compatable, meaning that it could feed from older Sten and Lanchester
magazines if the need ever arose. However, the opposite was not true.
Sten guns could not use the newer magazines from the Sterling.
The L2A3 version of the Sterling first appeared in 1956, and would
ultimately remain in British service for half a century. It was finally
replaced by the L85A1 in the 1990s. In a sense, the Sten gun lived on in
the Sterling, since the latter was so heavily influenced by the former.

the Culture Of the Sten:
The soldiers who carried the Sten gun often developed a true love/hate
relationship with it. It was rather ugly to many and not especially
ergonomic. It wasn't terribly accurate and had crude fixed sights. Its
magazines were really its weakest point. They were difficult to load
fully without the use of a tool, and even if one managed to do it, they
often were unreliable with more than 28 cartridges in them. Then again,
they were just plain unreliable thanks to the double column, single feed
design. This design also made them sensitive to dust, dirt, and mud.
This is why some militaries converted Sten mags over to single stack 20
rounders. Probably the biggest complaint though was that the gun wasn't
all that safe. Like many open bolt SMGs, the Sten could fire
accidentally if dropped on its butt or for that matter, if dropped at
all. The cocking piece safety lock was a late addition to the design,
though older guns were usually retrofitted to have it. Otherwise, the
Sten only had the bolt notch as its safety.
On the otherhand, the Sten was reasonably reliable and accurate when
kept in good working order and cleaned regularly. It was easy to learn
to use and to train others to use. Field stripping was also easy, along
with takedown on the MK II and V models. The gun was easy to store,
transport, and even hide. When assembled, it was quite lightweight and
compact. Most importantly, it was fast and cheap to produce, so Britan
was able to build millions during WWII, meaning its soldiers were given
enough firepower to do what needed doing. Few other firearm designs in
history have been so effective, at such a low cost. Considering the
Sten's counterpart in the British military was the bolt action Lee
Enfield No. 4 MK I, its rapid fire and large capacity were greatly
appreciated.
For all these reasons, and more, it was given several nicknames, such as
Plummer's Nightmare / Abortion and Stench Gun. There was even a famous
poem written about it by a soldier called "Owde To A Sten." Hey, the
Sterling never inspired poetry!

Gallery:
Sten MkI , probably museum picture:

Brit soldiers with Sten MkII

German officer examining Sten MkII

Gurkha with knife and part of Sten MKIV:

Israeli woman with Sten MkII:

Sten MkII next to Finnish (larger) Sten MKII:

Sten MKIIs Vietnam display case:

Sten Freak's Sten MKII:

Sten Freak's Sten MKII with short barrel and sling:

Sten Freak's Sten MkII with suppressor shown not attached:

The L34A1, a dedicated suppressed version of the Sterling:

Semi Stens:
As I said in the Intro, there have been few American companies who have
produced complete semi-auto only Sten carbines or pistols. CATCo
probably made the most and is the most well known today. Wiselite Arms,
the same folks who made the semi Sterling Sporter, received ATF approval
for a Sten MK III semi, but the carbine never went into production
beyond a few prototypes. Valkyrie Arms, of semi M3 Grease Gun fame, has
also offered a MK II semi pistol in limited numbers. What is more common
is for someone to buy an 80% complete semi receiver tube and try their
hand at making their own at home. Several outfits offer these DIY kits,
including Indianapolis Ordnance. I myself had my 3 semi Stens custom
built by an FFL-07 down in Florida, by the name of MK Gun Mods.
The ATF has several requirements for a civilian legal, semi-auto, Title 1
Sten gun. Obviously, the fire control group has to be modified in such a
way that it is incapable of automatic fire and can not easily be
modified to be made FA again. Second, the semi receiver tube can not
readily accept an original full-auto Sten bolt. Two methods are commonly
used to achieve this. In one, the inner diameter of the tube is smaller
than the outer diameter of a FA bolt. With the other, a blocking bar is
welded inside the tube, again so an unmodified FA bolt can't be
inserted.
Since 1981, the ATF has not allowed semi-auto Title 1 firearms to
operate from an open bolt. So semi Stens built since then have to be
made to fire from a closed bolt. This requires alteration to the bolt
itself, cocking handle, return spring, and firing pin. It also ties in
with modifications made to the FCG and possibly other parts, depending
on the exact method used. Finally, unless the build is to be an SBR,
something has to be done about the original 7.8" barrel. It can be used
as is, if the stock is omitted and replaced with a pistol grip. This
would be a Sten pistol. Alternatively, the original barrel can have an
extension added to it, to bring its overall length up to at least 16.1",
which would make it a carbine so it could legally have a stock. Of
course, rather than extending the original short barrel, one could
always simply purchase an American made 16.1" Sten barrel from any one
of a number of venders. Either way, a good bit of work goes into making a
solid and reliable (and ATF approved) semi-auto SMG.

My old CATCo SA-2:
I bought this carbine off an individual who was trading up to get an NFA
Sten gun. I kept it for a couple of years, and then traded it on
myself, to get a more authentic MK II clone. For what its worth, it
actually ran well for me.

My Sten MK II with loop stock and early production bronze bolt:
This is the MK II i sold the CATCo to get. I had it built with an
original bronze bolt, just because i thought it would be interesting. It
has a loop stock, complete with an original cleaning rod stored inside.
It also has an early cocking handle and screwed on dustcover. I like it
better than the CATCo because it has the J hook safety notch. Also, the
original selector switch has been converted to act as a manual safety.

My Sten MK III with standard t-stock:
This is my second MK III carbine from MKGM. I had this one built with
the J notch safety, which the first was lacking. It also has the second
sling swivel located on the buttstock. The cocking handle is a later
enlarged style, and the dustcover is dimple pressed on.

My Sten MK V with original wood furniture:
I had this MK V kit laying around for a bit, and it came with the
original barrel. I wanted to have it built up right and i think its the
best of the bunch. Its about as correct as one can get, while keeping
within ATF guidelines. It has the late style mushroom head cocking knob,
which was the one that acted as a push safety bolt lock.

MKGM Sten MK III Pistol:
This is a semi MK III pistol built by MKGM, complete with original 7.8"
barrel and paratrooper style rear grip in place of a buttstock. I sold a
couple of these on Gunbroker back during the Summer.

Valkyrie Arms Sten SAP2 Pistol:
Quite recently, Valkyrie Arms built up a few hundred Sten MK II pistols,
using original 7.8" barrels and custom rear grips. Unlike the CATCo and
MKGM guns, the Valkyrie are actually hammer fired, using a highly
modified AR15 FCG. These guns are built from MK III kits, which are
reworked to appear like MK IIs. I sold 3 of these last Spring and Summer
to various individuals.

My British mfg Sterling MK 6 Carbine:
Just for good measure and because it is fun to show off, this is my
original British made Sterling MK 6 Carbine. It was imported in the
early 1980s, and is as close as one can get to a factory semi Sten.

Final Thoughts:
The Sten is packed with history, which one can feel even when handling
semi-auto rebuilds. Its one of the most absolute utilitarian firearms
ever adopted by any military, and I am even including Russia in that
statement. Its fun to fire and play around with. Its even quite
'modular' especially for its day. For example, there are several stocks
that one can buy, which just snap right onto virtually any Sten. I've
seen folders and ones that adapt the gun to take an Enfield No.4 wood
stock. Parts and accessories are inexpensive at the moment, including
magazines, slings, and dropcases.
The Sten has little to no modern tactical usefulness, which is part of
the reason I like it so much. Its just WWII SMG fun, at its purest. In
the end, I am glad i discovered this type of firearm, even if i could
only afored semi-auto kit builds for my collection. They are still
enjoyable to take out shooting, and most of their parts do date back to
1940s Britan.
Sorry this thread took so long to complete. As with the one on the Uzi,
life kept getting in the way. Its done now though, and I hope you have
enjoyed reading it. I definitely enjoyed researching and writing it. If
you think this is a wall-o-text, you should see the information i had in
my notes that i decided not to include. So much out there on the good
o' Sten Machine Carbine.